only run renumbering unit test when clustalW is installed

modules/seq/alg/tests/test_renumber.py

@@ -112,6 +112,12 @@ class TestRenumber(unittest.TestCase):
 
 if __name__ == "__main__":
   # test renumbering
+  # test if clustalw package is available on system, otherwise ignore tests
+  try:
+    clustalw_path=settings.Locate(('clustalw', 'clustalw2'))
+  except(settings.FileNotFound):
+    print "Could not find clustalw executable: ignoring unit tests"
+    exit(0)  
   try:
     unittest.main()
   except Exception, e: